1. Field of the Invention
The present invention relates to a component mounting system in which an arbitrary mounting machine among a plurality of mounting machines arranged in alignment along a direction of conveying the circuit board can be equipped with a function of imaging, with a camera, an inspection target part of a circuit board and inspecting the inspection target part.
2. Description of the Related Art
In recent years, in order to easily support various forms of production of electronic component mounted board, as described in Japanese Unexamined Patent Application Publication No. 2004-104075, a module-type component mounting system has been developed in which a plurality of mounting machine modules arranged on a base in alignment along a direction of conveying the circuit board and the circuit board is conveyed to each mounting machine module in sequence for mounting a component on the circuit board. The patent gazette mentioned above describes that an inspection machine that inspects an inspection target part of a circuit board may be included in the module-type component mounting system.
However, a general-purpose inspection machine cannot be mounted on the base of the module-type component mounting system. Therefore, to mount an inspection machine on the base of the module-type component mounting system, a dedicated inspection machine module has to be newly manufactured with the size or installation structure of the inspection machine being changed according to the size or installation structure of the mounting machine module, thereby increasing a load in cost.
Moreover, depending on the type of a component to be mounted on the circuit board, the position of the inspection machine module may be required to be changed by exchanging the positions of the mounting machine module and the inspection machine module. For example, when a production job is such that a mounting machine module on an upstream side mounts an electronic component required to be shielded on a circuit board and a mounting machine module on a downstream side mounts a shielding case so as to cover the electronic component, the mounting state of the electronic component is preferably inspected before the shielding case is mounted. When a production job is such that any one of the mounting machine modules mounts a BGA-type component, the state of a mounting surface of the circuit board (for example, the presence or absence of a foreign substance) may preferably be inspected before the BGA-type component is mounted, in some cases.
However, in the structure described above, to change the position of the inspection machine module according to a change of the production job, an operation of changing the positions of the mounting machine module and the inspection machine module has to be performed, thereby disadvantageously causing the trouble of handling this operation to possibly decrease the operation rate of the component mounting system.
On the other hand, a mounting machine described in Japanese Unexamined Patent Application Publication No. 2007-318000 has a plurality of mounting heads removably mounted thereon. Any one of the mounting heads is replaced with a camera-equipped inspection head, and the component mounting state in the circuit board and others can be imaged by the camera in the mounting machine for inspection. In this mounting machine, an image signal output from the inspection head is processed by a control computer of the mounting machine. However, since image processing for inspection has a large load of arithmetic operation, difficult for a control computer of the mounting machine to concurrently perform a process of controlling the mounting operation and the image processing for inspection at high speed. For this reason, disadvantageously, the control computer of the mounting machine has to be replaced with a computer having a higher arithmetic processing performance, or the resolution (resolving power) of image processing for inspection is restricted to a low resolution with a small load of arithmetic operation to decrease inspection accuracy.